BACKGROUND: People with hemophilia A or B with inhibitors are at high risk of bleeding complications. Infusion of bypassing agents, such as recombinant activated FVII (rFVIIa) and plasma-derived activated prothrombin complex concentrate, are suggested as alternative therapies to factor VIII (haemophilia A) or IX (haemophilia B) for individuals who no longer respond to these treatments because they develop inhibitory antibodies. The ultimate goal of treatment is to preserve the individual's joints, otherwise destroyed by recurrent bleeds...

Vaccine development often encounters the challenge of virulence heterogeneity. Enterotoxigenic Escherichia coli (ETEC) bacteria producing immunologically heterogeneous virulence factors are a leading cause of children's diarrhea and travelers' diarrhea. Currently, we do not have licensed vaccines against ETEC bacteria. While conventional methods continue to make progress but encounter challenge, new computational and structure-based approaches are explored to accelerate ETEC vaccine development. In this study, we applied a structural vaccinology concept to construct a structure-based multiepitope fusion antigen (MEFA) to carry representing epitopes of the seven most important ETEC adhesins [CFA/I, CFA/II (CS1-CS3), CFA/IV (CS4-CS6)], simulated antigenic structure of the CFA/I/II/IV MEFA with computational atomistic modeling and simulation, characterized immunogenicity in mouse immunization, and examined the potential of structure-informed vaccine design for ETEC vaccine development...

Glycocholic acid (GCA) is an important metabolite of bile acids, whose urine levels are expected to be a specific diagnostic biomarker for hepatocellular carcinoma (HCC). A high-throughput immunoassay for determination of GCA would be of significant advantage and useful for primary diagnosis, surveillance and early detection of HCC. Single-chain variable fragment (scFv) antibodies have several desirable characteristics and are an attractive alternative to traditional antibodies for the immunoassay. Because chicken antibodies possess single heavy and light variable functional domains, it is an ideal framework for simplified generation of recombinant antibodies for GCA detection...

Despite years of effort and investment, there are few topical or systemic medications for skin wounds. Identifying natural "drivers" of wound healing could facilitate the development of new and effective treatments. When skin is injured, there is a massive increase of heat shock protein 90alpha (Hsp90α) protein inside the wound bed. The precise role for these Hsp90α proteins, however, was unclear. The availability of a unique mouse model that lacked the intracellular ATPase-driven chaperoning, but spared the extracellular F-5-supported pro-motility, function of Hsp90α allowed us to test specifically the role of the non-chaperone function of Hsp90α in normal wound closure...

Neisseria meningitidis is one of the main causes of sepsis and meningitis, which are two serious life-threatening diseases in both children and adolescents. Porin A (porA) from both serogroup A and B were cloned into the pET28a plasmid and expressed in E. coli BL21 (DE3). The protein was expressed in Escherichia coli BL21 (DE3) and confirmed by SDS-PAGE and Western blot analysis. BALB/c mice were subcutaneously injected three times with 25 μg of the recombinant PorA. Specific total IgG antibodies and isotypes were evaluated using ELISA assay...

Available rapid, simple and accurate methods for detection and diagnosis of emerging viral diseases are required. Recently, there was an urgent need for specific antibodies against mosquito-borne Zika virus (ZIKV), which is an emerging zoonotic disease of medical concern in different regions of the world. Here, we showed that overexpression of ZIKV antigens in ClearColi BL21(DE3), a bacteria strain expressing a non-endotoxic form of LPS, is suitable for the production of specific ZIKV antisera. Two major ZIKV antigenic domains, the domain III from envelope E glycoprotein, which brings the virus-specific epitopes, and the N-terminal region of nonstructural NS1 glycoprotein, which is responsible for pathophysiological conditions, were overexpressed in ClearColi BL21(DE3)...

The emergence and rapid spread of variant of the rabbit hemorrhagic disease virus (RHDV2) require new diagnostic tools to ensure that efficient control measures are adopted. In the present study, a specific sandwich enzyme-linked immunosorbent assay (ELISA) for detection of RHDV2 antigens in rabbit liver homogenates, based on the use of an RHDV2-specific monoclonal antibody (Mab) 2D9 for antigen capture and an anti-RHDV2 goat polyclonal antibody (Pab), was developed. This ELISA was able to successfully detect RHDV2 and RHDV2 recombinant virions with high sensitivity (100%) and specificity (97...

BACKGROUND: IgA antibody of Epstein-Barr virus (EBV) was found to associate with breast cancer, while the IgA positivity was related to a series of genetic markers in the genes of homologous recombination repair system (HRRs). We then assessed the associations of the polymorphisms in HRR genes with the risk and survival of breast cancer. MATERIALS AND METHODS: A case-control study was conducted with 1551 BC cases and 1605 age-matched healthy controls between October 2008 and March 2012 in the Guangzhou Breast Cancer Study (GZBCS), China, and the case population were followed up until January 31 2016...

Liposomes functionalized with monoclonal antibodies or their antigen-binding fragments have attracted much attention as specific drug delivery devices for treatment of various diseases including cancer. The conjugation of antibodies to liposomes is usually achieved by covalent coupling using cross-linkers in a reaction that might adversely affect the characteristics of the final product. Here we present an alternative strategy for liposome functionalization: we created a recombinant Fab antibody fragment genetically fused on its C-terminus to the hydrophobic peptide derived from pulmonary surfactant protein D, which became inserted into the liposomal bilayer during liposomal preparation and anchored the Fab onto the liposome surface...

Among the four known Streptococcal nucleases comprising of DNase A, B, C and D; DNase B is the most common, and determination of the levels of antibody to DNase B (ADB) is often used to confirm a clinical diagnosis of Streptococcus pyogenes/group A Streptococcal (GAS) infection. The commonly used assays for antibodies that neutralize DNase B or streptolysin O activity use partially purified antigens that often fail to detect antibody changes subsequent to culture documented infections. Therefore, an enzyme-linked immunosorbent assay (ELISA) was developed employing his-tagged recombinant DNase B as plate antigen for comparison to the commonly used DNA methyl green micromethod (DMGM)...

Several studies conducted in animal models for immunologically-mediated hypersensitivity diseases have shown that oral administration of antigens early in life can prevent the development of specific humoral and cellular immune responses and thus hypersensitivity reactions to the respective antigens. Such data were also obtained in models for Immunoglobulin E (IgE)-associated allergy, the most common hypersensitivity disease affecting more than 25% of the population. Based on data obtained in animal models for allergy several clinical intervention studies have been conducted in children to study if oral administration of materials containing allergens or allergen-derived peptides early in life can prevent the subsequent development of allergy...

Tuberculosis (TB) remains a main public health concern and 10.4 million new cases occurred in 2015 around the world. BCG is the only approved vaccine against TB, but has variable efficacy and new vaccines are needed. We developed two new mTB vaccine candidates based on the recombinant fusion proteins, rCMX and rECMXformulated with Advax4, a new combination adjuvant combining delta inulin, CpG oligonucleotide and murabutide. When BALB/c mice were immunized three times intramuscularly with these vaccine formulationsInjection of Advax4 alone increased the percentage of lymphatic endothelial cells and activated macrophages (F480/CD11b(+)) in the draining lymph nodes consistent with a chemotactic adjuvant effect...

Vav guanine nucleotide exchange factor 3 (Vav3), a Rho family GTPase, regulates multiple cell signaling pathways including those of T- and B-cell receptors in vertebrates through mediating the activities of the Rho family members. Whether the lamprey possesses Vav3 homolog and what role it plays in immune response remain unknown. Gene cloning, recombinant expression, antibody production and expression pattern analyses were performed to characterize the lamprey Vav3 in the current study. The lamprey Vav3 is closer to jawed vertebrates' Vav3 molecules (about 53% identities in general) than to Vav2 molecules of jawless and jawed vertebrates (about 51% identities in general) in sequence similarity...

Despite several decades of extensive research, the development of a highly efficacious malaria vaccine has yet to be accomplished. While the RTS,S malaria vaccine candidate shows the potential to prevent a substantial number of clinical malaria cases, significant improvements in protective efficacy are still needed. Multiple studies have shown that RTS,S induces protective antibody and CD4(+) T-cell responses, but limited or negligible CD8(+) T cells. In this study, we evaluated the immunogenicity and protective capacity of full-length recombinant P...

The unique differentiation of IgE cells suggests unconventional mechanisms of IgE memory. IgE germinal centre cells are transient, most IgE cells are plasma cells, and high affinity IgE is produced by the switching of IgG1 cells to IgE. Here we investigate the function of subsets of IgG1 memory B cells in IgE production and find that two subsets of IgG1 memory B cells, CD80(+)CD73(+) and CD80(-)CD73(-), contribute distinctively to the repertoires of high affinity pathogenic IgE and low affinity non-pathogenic IgE...

Toxoplasma gondii is an obligatory intracellular protozoan, which infects most of the warm-blooded animals, causing serious public health problems and enormous economic losses worldwide. The rhoptry effector protein 54 (ROP54) has been indicated as a virulence factor that promotes Toxoplasma infection by modulating GBP2 loading onto parasite-containing vacuoles, which can modulate some aspects of the host immune response. In order to evaluate the immuno-protective value of ROP54, we constructed a eukaryotic recombinant plasmid expressing T...

Recombinant biopharmaceuticals can induce generation of anti-drug antibodies, which could potentially neutralize therapeutic drug activity. In this report, we describe development and validation of a cell-based assay for detection of neutralizing antibodies (Nab) against insulin and insulin analogues. In order to achieve clinically meaningful sensitivity the method used an early signalling event, insulin induced insulin receptor phosphorylation as the endpoint. Percentage insulin receptor phosphorylation in cell lysates was measured using ECL based ELISA...